filelist: only scan parts of bucket when listing files

go.mod

@@ -5,21 +5,22 @@ module github.com/moov-io/ach-web-viewer
 go 1.20
 
 require (
+	cloud.google.com/go/storage v1.39.1
 	github.com/gorilla/mux v1.8.1
 	github.com/markbates/pkger v0.17.1
 	github.com/moov-io/ach v1.36.1
 	github.com/moov-io/base v0.48.5
 	github.com/moov-io/cryptfs v0.7.1
 	github.com/stretchr/testify v1.9.0
 	gocloud.dev v0.37.0
+	golang.org/x/sync v0.6.0
 )
 
 require (
 	cloud.google.com/go v0.112.1 // indirect
 	cloud.google.com/go/compute v1.25.0 // indirect
 	cloud.google.com/go/compute/metadata v0.2.3 // indirect
 	cloud.google.com/go/iam v1.1.6 // indirect
-	cloud.google.com/go/storage v1.39.1 // indirect
 	github.com/ProtonMail/go-crypto v0.0.0-20230828082145-3c4c8a2d2371 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cenkalti/backoff/v3 v3.2.2 // indirect
@@ -83,7 +84,6 @@ require (
 	golang.org/x/exp v0.0.0-20231206192017-f3f8817b8deb // indirect
 	golang.org/x/net v0.22.0 // indirect
 	golang.org/x/oauth2 v0.18.0 // indirect
-	golang.org/x/sync v0.6.0 // indirect
 	golang.org/x/sys v0.18.0 // indirect
 	golang.org/x/text v0.14.0 // indirect
 	golang.org/x/time v0.5.0 // indirect

pkg/filelist/bucket.go

@@ -9,10 +9,13 @@ import (
 	"path/filepath"
 
 	"github.com/moov-io/ach-web-viewer/pkg/service"
+	"github.com/moov-io/ach-web-viewer/pkg/yyyymmdd"
 	"github.com/moov-io/cryptfs"
 
+	"cloud.google.com/go/storage"
 	"gocloud.dev/blob"
 	_ "gocloud.dev/blob/gcsblob"
+	"golang.org/x/sync/errgroup"
 )
 
 type bucketLister struct {
@@ -71,9 +74,7 @@ func (ls *bucketLister) GetFiles(opts ListOpts) (Files, error) {
 		SourceType: "Bucket",
 	}
 	for i := range ls.paths {
-		files, err := ls.listFiles(opts, ls.buck.List(&blob.ListOptions{
-			Prefix: ls.paths[i],
-		}))
+		files, err := ls.listFiles(opts, ls.paths[i])
 		if err != nil {
 			return out, fmt.Errorf("error reading %s bucket path: %v", ls.paths[i], err)
 		}
@@ -122,7 +123,74 @@ func (ls *bucketLister) maybeDecrypt(r io.Reader) ([]byte, error) {
 	return initial, err
 }
 
-func (ls *bucketLister) listFiles(opts ListOpts, cur *blob.ListIterator) ([]File, error) {
+func (ls *bucketLister) listFiles(opts ListOpts, pathPrefix string) ([]File, error) {
+	// Different underlying storage engines will let us scan/glob parts of the bucket differently.
+	var gcsBucket *storage.Client
+	if ls.buck.As(&gcsBucket) {
+		return ls.listFilesFromGCSBucket(opts, pathPrefix)
+	}
+	return ls.listFilesFromCDKBucket(opts, pathPrefix)
+}
+
+func (ls *bucketLister) listFilesFromGCSBucket(opts ListOpts, pathPrefix string) ([]File, error) {
+	var g errgroup.Group
+	datePrefixes := yyyymmdd.Prefixes(opts.StartDate, opts.EndDate)
+
+	discoveredFiles := make(chan []File)
+
+	for _, datePrefix := range datePrefixes {
+		g.Go(func() error {
+			beforeList := func(as func(interface{}) bool) error {
+				var q *storage.Query
+				if as(&q) {
+					q.MatchGlob = fmt.Sprintf("%s/*/%s*/*", pathPrefix, datePrefix)
+				}
+				return nil
+			}
+
+			listOptions := &blob.ListOptions{
+				Prefix:     pathPrefix, //  + "/",
+				BeforeList: beforeList,
+			}
+
+			files, err := ls.listFilesFromCursor(opts, ls.buck.List(listOptions))
+			if len(files) > 0 {
+				go func() {
+					discoveredFiles <- files
+				}()
+			}
+			return err
+		})
+	}
+
+	err := g.Wait()
+	go func() {
+		discoveredFiles <- nil
+	}()
+	if err != nil {
+		return nil, err
+	}
+
+	var out []File
+	for {
+		files := <-discoveredFiles
+		if len(files) == 0 {
+			break
+		}
+		out = append(out, files...)
+	}
+	return out, nil
+
+}
+
+func (ls *bucketLister) listFilesFromCDKBucket(opts ListOpts, pathPrefix string) ([]File, error) {
+	return ls.listFilesFromCursor(opts, ls.buck.List(&blob.ListOptions{
+		Delimiter: "/",
+		Prefix:    pathPrefix,
+	}))
+}
+
+func (ls *bucketLister) listFilesFromCursor(opts ListOpts, cur *blob.ListIterator) ([]File, error) {
 	var out []File
 	for {
 		obj, err := cur.Next(context.Background())

pkg/yyyymmdd/prefix.go

@@ -0,0 +1,41 @@
+package yyyymmdd
+
+import (
+	"slices"
+	"time"
+)
+
+// Given two time.Time values generate a start and end prefix (in yyyy-mm-dd format)
+// which serves as prefixs usable to filter.
+//
+// Examples:
+//
+//	2023-12-23 to 2023-12-31 produces 2023-12-2, 2023-12-3
+//	2023-12-23 to 2024-01-10 produces 2023-12-2, 2023-12-3, 2024-01-0, 2024-01-10
+func Prefixes(start, end time.Time) []string {
+	var out []string
+
+	// For now just iterate over each day and chop off the trailing day digit
+	for {
+		if start.After(end) {
+			break
+		}
+
+		// Add the current day to our list
+		ts := start.Format("2006-01-02")
+
+		// Only when the end day is 10, 20, 30 we can extend the timestamp
+		if (start.Month() == end.Month()) && (start.Day() == end.Day()) && end.Day()%10 == 0 {
+			// do nothing
+		} else {
+			ts = ts[:len(ts)-1] // chop off the last digit
+		}
+
+		out = append(out, ts)
+
+		start = start.Add(24 * time.Hour)
+	}
+
+	slices.Sort(out)
+	return slices.Compact(out)
+}

pkg/yyyymmdd/prefix_test.go

@@ -0,0 +1,39 @@
+package yyyymmdd
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPrefixes(t *testing.T) {
+	start := time.Date(2023, time.December, 23, 0, 0, 0, 0, time.UTC)
+	end := time.Date(2023, time.December, 31, 0, 0, 0, 0, time.UTC)
+	expected := []string{"2023-12-2", "2023-12-3"}
+	require.ElementsMatch(t, expected, Prefixes(start, end))
+
+	end = time.Date(2024, time.January, 4, 0, 0, 0, 0, time.UTC)
+	expected = append(expected, "2024-01-0")
+	require.ElementsMatch(t, expected, Prefixes(start, end))
+
+	end = time.Date(2024, time.January, 10, 0, 0, 0, 0, time.UTC)
+	expected = append(expected, "2024-01-10")
+	require.ElementsMatch(t, expected, Prefixes(start, end))
+
+	end = time.Date(2024, time.January, 11, 0, 0, 0, 0, time.UTC)
+	expected = []string{"2023-12-2", "2023-12-3", "2024-01-0", "2024-01-1"}
+	require.ElementsMatch(t, expected, Prefixes(start, end))
+
+	end = time.Date(2024, time.January, 20, 0, 0, 0, 0, time.UTC)
+	expected = []string{"2023-12-2", "2023-12-3", "2024-01-0", "2024-01-1", "2024-01-20"}
+	require.ElementsMatch(t, expected, Prefixes(start, end))
+
+	end = time.Date(2024, time.January, 25, 0, 0, 0, 0, time.UTC)
+	expected = []string{"2023-12-2", "2023-12-3", "2024-01-0", "2024-01-1", "2024-01-2"}
+	require.ElementsMatch(t, expected, Prefixes(start, end))
+
+	end = time.Date(2024, time.January, 30, 0, 0, 0, 0, time.UTC)
+	expected = []string{"2023-12-2", "2023-12-3", "2024-01-0", "2024-01-1", "2024-01-2", "2024-01-30"}
+	require.ElementsMatch(t, expected, Prefixes(start, end))
+}